1. Technical Field
The disclosure relates to a control method for a polyphase step-up converter, and the polyphase step-up converter. For example, the disclosure relates to a control method for a polyphase step-up converter that includes a plurality of step-up converters connected in parallel with each other and that controls the plurality of step-up converters with the use of a plurality of driving signals having different phases, and the polyphase step-up converter.
2. Description of Related Art
There is a polyphase step-up converter as one of step-up converters. The polyphase step-up converter includes a plurality of step-up converters connected in parallel with each other and controls the plurality of step-up converters with the use of a plurality of driving signals having different phases. The polyphase step-up converter is allowed to reduce a load per one phase at a high load as compared to a single-phase step-up converter, so a reduction in size is possible. An example of the polyphase step-up converter is described in Japanese Patent Application Publication No. 2014-042410 (JP 2014-042410 A).
The polyphase step-up converter described in JP 2014-042410 A includes a circuit in which a switch and a reactor are connected in parallel with each other between an output terminal of the polyphase step-up converter and a load circuit to which a stepped-up voltage generated by the polyphase step-up converter is supplied. In the polyphase step-up converter described in JP 2014-042410 A, the reactor is switched between an active state and an inactive state with the switch. Thus, the polyphase step-up converter described in JP 2014-042410 A avoids a resonance phenomenon that occurs as a result of coincidence of a ripple component of an output signal of the polyphase converter with a resonance frequency of a resonance circuit formed of a smoothing capacitor connected to the output terminal of the polyphase step-up converter and an inductor that parasitizes a wire connected to the output terminal.
However, the technique described in JP 2014-042410 A requires the circuit in which the switch and the inductor are connected in parallel with each other. Generally, an inductor has a large volume and weight. For this reason, when the resonance phenomenon of a system including a polyphase step-up converter is avoided with the technique described in JP 2014-042410 A, the volume and weight of the system are large.